Heat engine

ABSTRACT

A closed cycle engine has a large volume power chamber, a large volume displacement chamber and two small equal volume displacement chambers all mechanically interconnected out of phase to successively pass separate bodies of working fluid through the system with heat flow either to or from the fluid on movement of fluid from one chamber to another.

United States Patent 1191 Spriggs 51 Aug. 20, 1974 I5 HEAT ENGINE 3,487,635 1/1970 Prast et al 60 520 lnvcnmrz James 0. p gg Kensington Md. 3,608,311 9/1971 Roesel, Jr. 60/520 X 20795 Primary ExaminerEdgar W. Geoghegan [22] Filed: June 7, 1973 Assistant Examiner-H. Burks, Sr.

Attorney, Agent, or Firm-Shlesinger, Arkwright, [21] Appl. No.. 368,006 Garvey & Dinsmore Related U.S. Application Data [63] Continuation of Ser. NO. 166,769, July 28, 1971. 1 [57] ABSTRACT A closed cycle engine has a large volume power cham- [52] U.S. Cl. 60/520 bet, a large volume displacement chamber and two [51] Int. Cl. F02g l/04 small equal volume displacement chambers all me- [58] Field of Search 60/518, 520 chanically interconnected out of phase to successively pass separate bodies of working fluid through the sys- [56] References Cited tem with heat flow either to or from the fluid on UNITED STATES PATENTS movement of fluid from one chamber to another. 3,115,014 12/1963 Hogan 60/518 X 24 Claims, 4 Drawing Figures Qin 30 l 44 94 t g F 92 4e 52 r 86 as 50 n IOO -60 Q out Q 1 as Qout PATENTfimuszo I974 SEETIUF 2 Joell:

IN VEN TOR.

BY JAMES O. SPRIGGS 5 1 ATTORAIZD HEAT ENGINE This is a continuation of application Ser. No. 166,769, filed July 28, 1971.

BACKGROUND OF INVENTION This invention relates to a new type of prime mover, and in particular to an improvement in external combustion, closed cycle units.

During the past twenty years renewed research efforts have been undertaken to develop a more thermally efficient prime mover. One of the areas of investigation undertaken by companies both in the United States and in Europe, has been the perfection of the closed cycle engine. Considerable development work and progress on a practical Stirling closed cycle engine has been one of the achievements in this regard.

This type of engine, being a closed cycle external combustion type permits the use of any heat volume including combustors with operating conditions and a wide variety of fuels whose products of combustion are less noxious than currently is true for conventional internal combustion engines.

Other advantages of this particular type of engine are less sound and vibration, favorable torque characteristics, easy starting, greater thermal efficiency, and lower peak to mean pressure ratios. The basic invention isreversible and can be used also as a refrigerator or heat pump.

This invention contemplates an improvement wherein it is possible to conform the several phases of the cycle more closely to the isothermal, isobaric, and isochoric processes of either the Stirling or Ericsson cycles, or to other polytropic processes.

Accordingly, it is a principal object of this invention to provide an improvement in closed cycle engines that will provide for greater thermal efficiency and flexibility of design of these units.

DESCRIPTION OF DRAWINGS FIG. 1 shows a pressure-volume (P-V) diagram for a Stirling cycle engine.

FIG. 2 shows a piston modification of the subject invention.

FIG. 3 shows a modification of the invention using rotary fluid pump units.

FIG. 4 shows another modification of the invention wherein double-acting pistons are used.

DESCRIPTION OF THE INVENTION This invention has application to several types of thermodynamic work cycles, such as the Ericsson and Stirling cycles. For illustration purposes, however, the exemplary description is confined to the Stirling cycle. FIG. 1 shows a Pressure-Volume diagram for a Stirling cycle.

The high pressure and high temperature point 12 of the working fluid shows its state at the beginning of the expansion stroke, from where it travels along the high temperature isothermal expansion line 14 T with heat Q being added during the phase until the expanding of fluid reaches state 16 at maximum volume and maximum temperature, performing useful work during the expansion. From this point the fluid passes through a constant volume state passing downwardly along line 18 giving up heat, Q over the spectrum of temperatures from T,, to T, where the low temperature, maximum volume state shown at 20 is reached. From this point the fluid is compressed while heat, O is removed, proceeding in the direction of the arrow along isothermal line 22 T to point 24. The fluid at point 24 is at minimum temperature and volume. The fluid is then heated, QTeg, at constant volume, building up the pressure and temperature as it proceeds along the constant volume (isochoric) line 26 to return to the starting point 12 which represents the fluid at maximum pressure and temperature. Note that the heat taken from the fluid as it proceeds downwardly along constant volume line 18 is transferred and applied to the fluid as it proceeds upwardly along the constant volume line 26 by a regenerator unit, diagramatically indicated at 58 in FIG. 2.

The regenerator consists of one or more pairs of conduits with the conduits of each pair in close thermal contact with each other, as for instance would be the case if one conduit were concentric with the other. The flow of fluid is in opposite directions in each conduit of a pair so that the temperature differential between adjacent portions of the conduits is minimized.

In FIG. 2, a piston version of the invention is illustrated at 30. A heater 32 supplies heat input to the enclosed fluid passing through its coil 34 along line 36 and through bi-directional valve 38 into the high temperature, large volume work cylinder 40. The piston 42 is pressed downwardly during this portion of the cycle which corresponds to the phase of the fluid shown on the Pressure-Volume diagram of FIG. 1 between points 12 and 16 as it moves along the isothermal expansion line 14.

The work cylinder piston 42 moves the work cylinder piston rod 44 downwardly during this expansion turning the crankshaft 46 which is connected thereto at 48. A small flywheel 50 is mounted on the output shaft section 52 of the crankshaft 46.

As the crankshaft-flywheel assembly moves the power piston 42 of the work cylinder upward, the ,bidirectional valve 38 is switched to direct flow of the fluid leaving the power cylinder 40 into the regenerator conduit 54 which conducts the fluid to the high temperature input line 56 of the regenerator 58.

The fluid passes through the coil 60, giving off heat as it does so, and leaves the low temperature side of the regenerator 58, passing through conduit 62 and twoway valve 64, entering the large volume displacer cylinder 66. Intake of the expansible fluid is governed by the movement of displacer cylinder 68 which is mechanically connected through piston rod 70 to the crankshaft 46. The movement of the expansible fluid from the large volume work cylinder 40 to the large volume displacer cylinder 66 corresponds to the movement on the Pressure-Volume diagram of FIG. 1 from point 16 to point 20 along constant volume line 18. FIG. 2, however, shows the work cylinder and the displacement cylinder, as well as the valve settings as they would appear for the power expansion phase of the cycle along line 14 of FIG. 1.

When the displacer piston 66 moves downward it forces the cooled low pressure fluid charge out of the cylinder and through the two-way valve 64 and conduit 72 to the cooler 74 where it passes through the cooling coil 76 and the conduit 78 through the bi-directional valve 80 through which it passes into the small volume, low temperature displacer cylinder 82.

Most of the volume of fluid will be received within the small-volume displacer cylinder, inasmuch as all of the conduit liner and the cooling or heating coils of the system are small in size and accommodate only a fraction of the volume of the cylinders of the system.

With reference to FIG. 1, the state of the expansible fluid changes in the direction of the arrow along isothermal line 22 from point to the low temperature, low volume point 24. The smaller volume displacer piston 84 is connected through its piston rod 86 to the small crank 88 by a bearing connection 90.

The small crankshaft end 92 is shown broken away in the drawing, but it is connected 180 out of phase to the large crankshaft 46. The angular direction of travel of the crank 88 is shown by the arrow 94.

The system is operated with two separate bodies of fluid which are spaced apart in the system and controlled by operation of the pistons. When one body is going through the isothermal expansion work phase and taking on heat from the heater 32, the second body of fluid is passing through the isothermal compression stage and giving heat up to the heat sink 74. Correspondingly, when one body of fluid is being displaced from one large cylinder to the other, it is giving off heat to the regenerator which is simultaneously heating the body of fluid being displaced between the small cylinders.

When the piston 84 starts on its downward stroke, the position of the bi-directional valve 80 is changed so that conduit 78 is blocked and conduit 96 is opened permitting the cooled compressed fluid to pass through the conduit 96 to the low temperature side T, of the regenerator 58 and through its heat output coil 100 where it picks up heat from the heat input coil 60, increasing its temperature and pressure. On leaving the coil 100 it passes through the conduit 102 and bidirectional valve 104 to the small volume, high pressure, high temperature cylinder 106. I

This thermodynamic phase is shown in FIG. 1 by the line 26, where the low temperature, low pressure and displacer piston 108 is connected by the piston rod 110 to the crank 88 by a bearing connection generally indicated at 90. Piston 108, as shown, is 180 out of phase with its matching small volume piston 84.

On intake, piston 108 moves downwardly to bottom dead center position. At this point the bi-directional valve 104 changes position and the piston 108 returns upwardly displacing the high pressure, high temperature fluid out through line 112 to the heater 32, completing the cycle.

Although the large cylinders are shown equal to each other in diameter as are the small cylinders, relative displacements of these pairs of cylinders may be changed to obtain other than the constant volume process of the Stirling cycle, with corresponding deviations of the slope of lines 18 and 26 in FIG. 1. For instance, a more constant pressure process would reduce the peak pressure at point 12 to advantage.

It is also possible to use a compound system with compound expansion and compression with prior interstage heating and cooling respectively, such as in a compound steam engine.

For greater efficiency it is possible to add heat to the expanding fluid by supplying heat through the cylinder walls of the large cylinder and also removing heat from the fluid in the displacement chambers as shown in FIG. 2.

It should be noted that when the working fluid is a two phase fluid such as steam, the difference in relative sizes between the large and small volume cylinder is very large, being on the order of 1,000. When steam is used the heat sink is a condenser while the heater is a boiler, and the small displacement cylinders act as a pump.

An illustrative rotary displacer or pump modification of the invention is shown in FIG. 3, wherein heat is applied to the working fluid by the heater 120 and it subsequently flows through the conduit or line 122 and into the large volume power expansion chamber 124.

, The rotor 126 is mounted on a rotating shft 128 eccentrically disposed in cylinder 124 and has an impeller receiving slot 130. The impeller 132 is spring-biased so that its edge continually engages the inner wall of the cylinder for the entire arc of rotation of the rotor 126. Rotors 126, 146, 162, and 176 are mechanically connected with each other.

As the rotor 126 turns clockwise the fluid leaves the conduit 122 and fills the expanding chamber section 134 which occupies the entire space within the cylinder behind the advancing impeller vane 132 as it sweeps through the cylinder in a clockwise direction.

In this modification there are four discrete and separate bodies of working fluid. The second body of such fluid is initially contained in the section of the cylinder 135 disposed immediately in front of the impeller vane 132. This body is swept through the cylinder and into the conduit line 136 to the regenerator unit 138, where it passes through the input regenerator coil 140 giving off heat. It passes out of the regenerator and through the line 142 to the large volume displacement cylinder 144 which has a clockwise rotating rotor 146 disposed therein similar in construction to rotor 126 and mechanically connected thereto. The impeller vane 148 is maintained in phase relationship with the impeller vane 132 of the expansion work cylinder 124, so that the expansible fluid is moved into an expanding chamber area 150 behind the impeller vane 148 as the volume of cavity 135 decreases.

Similarly, there is a third body of fluid disposed in front of the impeller 148 in the variable cavity 151, which is moved out of the cylinder 144 and through the line 152 to the cooler coil 156 and out through the conduit line 158 to the small volume displacer cylinder 160. The cylinder has an eccentrically disposed rotor 162 and is of similar construction and operation as the large cylinders previously described. The rotor moves in a clockwise direction and has a retractable impeller 164 which engages the inner surface of the cylinder to form a receiving chamber 166 which enlarges as the rotor 162 sweeps in a clockwise direction. Movement of the rotor 162 is synchronized in phase mechanically with the larger rotors, although displaced in the figure for convenience in illustration.

With the position of the rotors shown, the various phases are at their midpoints, with the third body of fluid which is in the low temperature isothermal compression phase, indicated as line 22 in FIG. 1. The expansible fluid ahead of the impeller 148 in the chamber section 151 is being moved out and through the cooler 154 and into the small volume expanding section 166 behind the impeller 164.

The fourth body of working fluid is disposed in the section 167 immediately in front of the impeller 164 and is being moved out through the conduit line 168 and through the output coil of regenerator 170 where it is heated and moved out under high pressure and temperature along line 172 to the small volume, high pressure and temperature displacement cylinder 174. The cylinder is of the same size (in the Stirling cycle configuration) and has the same construction as the low pressure, low temperature small volume displacement cylinder 160. Its rotor 176 rotates in a clockwise direction in phase with the rotor 162 and has a reciprocally mounted impeller 178 which engages the walls of the cylinder 174.

The fluid enters the cylinder behind the impeller 178 occupying the expanding section 180. The impeller 178 is shown having swept half the crescent shaped cross section of the cavity between the cylinder 174 and the eccentrically mounted rotor 176.

The impeller 178 is shown in the position of forcing outwardly a portion of the first body of expansible fluid occupying the cavity 181 immediately in front of the impeller 178 into the conduit line 182 leading to the coil 184 of the heater 120. In the above-identified embodiments the working fluid is an expansible or condensible gas. The mean effective working fluid pressure should be as high as is consistant with structural and sealing considerations in order to achieve the greatest specific power. Temperatures, when the system is used as a power source rather than a refrigerator, will typically be l500 Rankine or more for the source, limited by materials and lubrication considerations, and 540 Rankine for the sink, as in the pressure-volume diagram of FIG. 1.

The volume of the conduit and heat exchange assemblies is a very small percentage of the volume of the cylinders, so that for practical purposes the volumes of working fluid can be considered as occupying only the cylinder volumes.

Each phase is separate and completed with each complete movement of the piston or rotor of the units described. This arrangement makes possible the use of separate masses of working fluid which are carried through the system simultaneously resulting in greater power output and proportionally less mechanical losses. The arrangement of the elements is such that the work expansion phase at high pressure and temperature occurs simultaneously with the negative or compressor work phase at low pressure and temperature. lnasmuch as there is a direct mechanical connection between the working elements, only a small flywheel or other energy storage device is needed to supply the work needed during the displacement phase.

A primary feature of the invention is, then, that the external heat addition and rejection functions of a heat engine are performed on the working fluid in conjunction with positive and negative work functions during one phase of operation. The regenerative function that changes the temperature of the fluid is performed during a separate phase. This permits regeneration either by a distributed temperature heat exchanger or by a mechanical energy storage device or by any combination of heat and mechanical energy exchange between the downward and upward temperature changing phases. Accordingly, the pressure-volume relationship in the fluid during temperature translation can be controlled to any desired value in the primary embodiment, by the choice of values, severally and individually, of the four displacements. This choice permits approximation of any polytropic process between the essentially isothermal heat addition and rejection phases. If a different process is selected for the upward translation than for the downward, heat must be supplied to or removed from the working fluid to equal the work removed from or supplied to the fluid. it will be seen that the Stirling, Ericsson, and Carnot cycles are special cases of this general cycle that can be approximated by proper proportioning of the four swept volumes. The approximation can be closer than in other forms of heat engines.

One constraint on the double-acting embodiment of FIG. 4 is that it is limited to the constant-volume (Stirling cycle) temperature translation. Another constraint on the basic cycle is that, if a two-phase fluid such as water-stream is used, its near incompressibility at volumes below the saturated liquid margin limits the possible ratios of small hot and cold volumes and of small and large cold volumes.

Another feature of the invention is that the heat is added and rejected during the differential expansion and compression work phases at more nearly constant temperatures than in other heat engines, with correspondingly increased thermodynamic efficiency.

Another feature of the invention is that all the components of the system are exposed to nearly constant working fluid temperatures throughout each cycle, minimizing the irreversible heat losses incurred during heat exchanges between the fluid and the adjacent component walls.

With respect to the dobule-acting piston unit, the high temperature cylinders are disposed internally adjacent each other, while the low temperature volumes are disposed externally for ready conduction to the ambient temperature surroundings.

Many different types and combinations of valve or porting arrangements for the working fluid are possible, including flap or pressure operated valves, and spool valves. For simplicity, the invention has been described with bi-directional valves as part of the system.

The working fluid is mentioned above as being an expansible gas, such as helium, which has a high specific heat and a low coefficient of friction or a condensible gas such as steam. Hydrogen could also be used, as well as other available expansible gases such as carbon dioxide.

A two-phase fluid such as steam could also be used as the working fluid with the constraints mentioned previously. However, modifications to the system, combining flow processes with the fundamentally non-flow or discrete processes of the basic cycle may be used. In an arrangement such as this, steam would be produced in a monotube boiler or high temperature heat exchanger. Steam would be passed into the large volume, work expansion chamber at constant pressure and temperature continuously as the piston is moved before it. On the return stroke the steam will pass through the regenerator and into the large volume displacement cylinder, partly condensing as it does so. Further condensing will occur when the fluid mixture is passed through the cooler. A liquid accumulator system is provided to collect the condensed fluid in the cooling phases and to pass it through the regenerator where it is heated to the highest temperature of the system, before being again returned to the closed cycle through the boiler unit. This gaseous-liquid cycle accentuates the advantages of the small variation in temperature of the various parts of the system since the high conductivity of wet steam in contact with conductor surfaces would not present a heat loss problem.

Since the invention is thermodynamically reversible, any of the embodiments described, as well as others that may be derived therefrom, may be employed as heat pumps or refrigerators by supplying mechanical power to what has been described as a mechanical output, the input and output heat exchangers performing their functions in reverse fashion.

While this invention has been described in connection with different embodiments thereof, it will be understood that it is capable of further modifications, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth and fall within the scope of the invention or the limits of the appended claims.

What I claim is:

l. A closed cycle heat engine, comprising:

a. a large volume expansible work chamber means for receiving heated expansible working fluid under pressure producing a mechanical work output and subsequently forcing it therefrom to be cooled.

b. a large volume expansible displacement chamber means substantially equal in volume to and activated 180 out of phase from the work chamber means for receiving the working fluid after it leaves the work chamber means and subsequently forcing it therefrom,

c. regenerator means connected between the work chamber means and the displacement chamber means for cooling the working fluid as it passes from the work chamber means to the displacement chamber means,

d. a small volume, low temperature expansible chamber displacement means having a volume substantially smaller than that of the large volume displacement chamber means for receiving cooled working fluid from the large volume displacement means after further heat has been removed and subsequently forcing it through the system to be heated,

e. heat sink means connected between the large volume displacement chamber means and the small volume displacement chamber means for removing heat from the fluid at the low temperature value of the cycle as it passes therethrough. small volume, high temperature, high pressure displacement means substantially equal in volume and activated 180 out of phase from the small volume, low temperature displacement chamber means for receiving working fluid thereform and subsequently forcing it to the large volume expansible work chamber means,

g. the regenerator means being connected between the low temperature and high temperature small volume displacement means for heating the working fluid as it passes therethrough,

h. heater means connected between the high temperature, high pressure, small volume displacement means and the large volume expansible work chamber means for receiving fluid from the small volume, high temperature, high pressure displacement means and supplying heat to it as it passes therethrough.

2. The closed cycle heat engine as set forth in claim 1, wherein:

valve means is connected to each of the expansible chamber means for directing discrete bodies of working fluid into and out of the expansible means and from one heat exchanger means to another.

3. The closed cycle heat engine as set forth in claim 1, wherein:

the relative volumes of the large and small expansion chambers, and the amount of heat flowing through the heat exchangers as the working fluid passes therethrough are selected so that the change in state of the fluid closely follows the theoretical thermodynamic change in state desired for a given phase.

4. The closed cycle heat engine as set forth in claim 1, wherein:

the working fluid is an expansible gaseous substance having a high specific heat and low coefficient of friction. 5. The closed cycle heat engine as set forth in claim 2, wherein:

the working fluid is helium.

6. The closed cycle heat engine as set forth in claim 2, wherein:

the working fluid is hydrogen.

7. The closed cycle heat engine as set forth in claim 1, wherein:

the upper pressure limits of the fluid is approximately atmospheres.

8. The closed cycle heat engine as set forth in claim 1, wherein:

the temperature range of the working fluid varies between approximately 540 Rankine and l500 Rankine.

9. The closed cycle heat engine as set forth in claim 1, wherein:

the expansion chamber volumes and heat input ratios are balanced to give approximately isothermal changes of the pressure volume relationship of the fluid at the high and low temperatures.

10. The closed cycle heat engine as set forth in claim 8, wherein:

the volume of the heat exchange means are a small fraction of the volume of the smaller variable volume chamber.

11. The closed cycle heat engine as set forth in claim 1, wherein:

a. the large volume expansible work chamber means is disposed adjacent to a heat source and permits heat to pass into the expanding working fluid,

b. the low temperature displacement chamber means is disposed adjacent to a heat sink and permits heat to pass from the working fluid to the heat sink.

12. The closed cycle heat engine as set forth in claim 1, wherein:

a. the large volume work expansion means includes a cylinder and a piston having a piston rod connected to an output shaft,

b. the displacement chamber means includes a cylinder and a piston.

13. The closed cycle heat engine as set forth in claim 12, wherein:

a. the output shaft is a crankshaft,

b. the pistons of the displacement cylinders are connected thereto.

14. The closed cycle heat engine as set forth in claim 12, wherein:

a. the small volume chamber means are connected in double-acting configuration,

b. the large volume chamber means are connected in double-acting configuration.

15. The closed cycle heat engine as set forth in claim 12, wherein:

valve means is connected between each of the chamber means and the adjacent heat exchange means for successively directing the working fluid into a cylinder at piston top dead center and out of the cylinder when the piston reaches bottom dead center.

16. The closed cycle heat engine as set forth in claim 1, wherein:

a. the expansible chambers include a hollow cylinder and an eccentrically mounted cylindrical rotor of smaller diameter which has its periphery at one point in contact with the inner surface of the cylinder at one point,

b. the rotors each having a radially disposed reciprocally movable outwardly biased impeller which is in continual sliding contact with the inner surface of the cylinder wall,

c. an inlet port disposed on one side and close to the point of contact of the cylinder and the rotor, and an outlet port disposed on the other side of the line of contact between the cylinder and the rotor.

17. The closed cycle heat engine as set forth in claim 16, wherein:

a. the rotor is a solid cylindrical member which has a radial slot therethrough, b. an impeller blade reciprocally mounted within the slot, c. biasing means disposed between the innermost radial surface of the slot and the impeller for forcing the impeller outward in a radial direction against the cylinder inner surface. 18. The closed cycle heat engine as set forth in claim 17, wherein:

biasing means is a spring.

19. The closed cycle heat engine as set forth in claim 12, wherein:

a. the working fluid is a two-phase fluid,

b. the heating means is a boiler,

c. the regenerator and heat sink means includes liquid accumulator means for collecting condensed liquid and for supplying it to the boiler. 20. The closed cycle heat engine as set forth in claim 12, wherein:

a. the working fluid is a two-phase fluid,

b. the large volume expansible chamber means is several orders of magnitude larger than the small volume low temperature displacement chamber means,

c. the heating means is a boiler,

d. the regenerator and heat sink means cool and liquify the working fluid, and

e. the regenerator means vaporizes the working fluid during the heating portion of the cycle.

21. The closed cycle heat engine as set forth in claim 19, wherein:

the working fluid is steam.

22. In a heat converter assembly:

a. conduit means through which an expansible gas circulates,

b. heat exchanger means connected to the conduit means at one end for effecting heat transfer between the gas within the conduit means and the immediate area of the heat exchanger,

c. a bi-directional valve connected to the conduit means at its other end and through which the expansible gas passes,

d. a first variable volume means connected to one conduit in the bi-directional valve means for receiving expansible gas from the valve and changing the volume thereof,

e. a second variable volume means of the same capacity as the first variable volume means and being out of phase therewith, which is connected to a second conduit within the bi-directional valve,

f. the bi-directional valve having means for alternately interconnecting through their respective conduits the first variable volume means with the second variable volume means, and the first variable volume means with the conduit means,

g. mechanical means connected to both the first and second variable volume means.

23. In the heat converter assembly as set forth in claim 22. wherein:

a. a second bi-directional valve is connected between the first and second variable volume means,

b. a second heat exchanger means is connected between the first and the second bi-directional valve, and

c. the second bi-directional valve means includes means for alternately connecting the first and second variable valve means, and the second variable volume means with the second heat exchanger means.

24. In the heat converter assembly as set forth in claim 23, wherein:

a. heat regenerator means is interconnected between the first and second variable volume means. 

1. A closed cycle heat engine, comprising: a. a large volume expansible work chamber means for receiving heated expansible working fluid under pressure producing a mechanical work output and subsequently forcing it therefrom to be cooled, b. a large volume expansible displacement chamber means substantially equal in volume to and activated 180* out of phase from the work chamber means for receiving the working fluid after it leaves the work chamber means and subsequently forcing it therefrom, c. regenerator means connected between the work chamber means and the displacement chamber means for cooling the working fluid as it passes from the work chamber means to the displacement chamber means, d. a small volume, low temperature expansible chamber displacement means having a volume substantially smaller than that of the large volume displacement chamber means for receiving cooled working fluid from the large volume displacement means after further heat has been removed and subsequently forcing it through the system to be heated, e. heat sink means connected between the large volume displacement chamber means and the small volume displacement chamber means for removing heat from the fluid at the low temperature value of the cycle as it passes therethrough. f. small volume, high temperature, high pressure displacement means substantially equal in volume and activated 180* out of phase from the small volume, low temperature displacemenT chamber means for receiving working fluid thereform and subsequently forcing it to the large volume expansible work chamber means, g. the regenerator means being connected between the low temperature and high temperature small volume displacement means for heating the working fluid as it passes therethrough, h. heater means connected between the high temperature, high pressure, small volume displacement means and the large volume expansible work chamber means for receiving fluid from the small volume, high temperature, high pressure displacement means and supplying heat to it as it passes therethrough.
 2. The closed cycle heat engine as set forth in claim 1, wherein: valve means is connected to each of the expansible chamber means for directing discrete bodies of working fluid into and out of the expansible means and from one heat exchanger means to another.
 3. The closed cycle heat engine as set forth in claim 1, wherein: the relative volumes of the large and small expansion chambers, and the amount of heat flowing through the heat exchangers as the working fluid passes therethrough are selected so that the change in state of the fluid closely follows the theoretical thermodynamic change in state desired for a given phase.
 4. The closed cycle heat engine as set forth in claim 1, wherein: the working fluid is an expansible gaseous substance having a high specific heat and low coefficient of friction.
 5. The closed cycle heat engine as set forth in claim 2, wherein: the working fluid is helium.
 6. The closed cycle heat engine as set forth in claim 2, wherein: the working fluid is hydrogen.
 7. The closed cycle heat engine as set forth in claim 1, wherein: the upper pressure limits of the fluid is approximately 100 atmospheres.
 8. The closed cycle heat engine as set forth in claim 1, wherein: the temperature range of the working fluid varies between approximately 540* Rankine and 1500* Rankine.
 9. The closed cycle heat engine as set forth in claim 1, wherein: the expansion chamber volumes and heat input ratios are balanced to give approximately isothermal changes of the pressure volume relationship of the fluid at the high and low temperatures.
 10. The closed cycle heat engine as set forth in claim 8, wherein: the volume of the heat exchange means are a small fraction of the volume of the smaller variable volume chamber.
 11. The closed cycle heat engine as set forth in claim 1, wherein: a. the large volume expansible work chamber means is disposed adjacent to a heat source and permits heat to pass into the expanding working fluid, b. the low temperature displacement chamber means is disposed adjacent to a heat sink and permits heat to pass from the working fluid to the heat sink.
 12. The closed cycle heat engine as set forth in claim 1, wherein: a. the large volume work expansion means includes a cylinder and a piston having a piston rod connected to an output shaft, b. the displacement chamber means includes a cylinder and a piston.
 13. The closed cycle heat engine as set forth in claim 12, wherein: a. the output shaft is a crankshaft, b. the pistons of the displacement cylinders are connected thereto.
 14. The closed cycle heat engine as set forth in claim 12, wherein: a. the small volume chamber means are connected in double-acting configuration, b. the large volume chamber means are connected in double-acting configuration.
 15. The closed cycle heat engine as set forth in claim 12, wherein: valve means is connected between each of the chamber means and the adjacent heat exchange means for successively directing the working fluid into a cylinder at piston top dead center and out of the cylinder when the piston reaches bottom dead center.
 16. The closed cycle heat engine as set forth in claim 1, wherein: a. the expansible chambers include a hollow cylinder and an eccentrically mounted cylindrical rotor of smaller diameter which has its periphery at one point in contact with the inner surface of the cylinder at one point, b. the rotors each having a radially disposed reciprocally movable outwardly biased impeller which is in continual sliding contact with the inner surface of the cylinder wall, c. an inlet port disposed on one side and close to the point of contact of the cylinder and the rotor, and an outlet port disposed on the other side of the line of contact between the cylinder and the rotor.
 17. The closed cycle heat engine as set forth in claim 16, wherein: a. the rotor is a solid cylindrical member which has a radial slot therethrough, b. an impeller blade reciprocally mounted within the slot, c. biasing means disposed between the innermost radial surface of the slot and the impeller for forcing the impeller outward in a radial direction against the cylinder inner surface.
 18. The closed cycle heat engine as set forth in claim 17, wherein: biasing means is a spring.
 19. The closed cycle heat engine as set forth in claim 12, wherein: a. the working fluid is a two-phase fluid, b. the heating means is a boiler, c. the regenerator and heat sink means includes liquid accumulator means for collecting condensed liquid and for supplying it to the boiler.
 20. The closed cycle heat engine as set forth in claim 12, wherein: a. the working fluid is a two-phase fluid, b. the large volume expansible chamber means is several orders of magnitude larger than the small volume low temperature displacement chamber means, c. the heating means is a boiler, d. the regenerator and heat sink means cool and liquify the working fluid, and e. the regenerator means vaporizes the working fluid during the heating portion of the cycle.
 21. The closed cycle heat engine as set forth in claim 19, wherein: the working fluid is steam.
 22. In a heat converter assembly: a. conduit means through which an expansible gas circulates, b. heat exchanger means connected to the conduit means at one end for effecting heat transfer between the gas within the conduit means and the immediate area of the heat exchanger, c. a bi-directional valve connected to the conduit means at its other end and through which the expansible gas passes, d. a first variable volume means connected to one conduit in the bi-directional valve means for receiving expansible gas from the valve and changing the volume thereof, e. a second variable volume means of the same capacity as the first variable volume means and being 180* out of phase therewith, which is connected to a second conduit within the bi-directional valve, f. the bi-directional valve having means for alternately interconnecting through their respective conduits the first variable volume means with the second variable volume means, and the first variable volume means with the conduit means, g. mechanical means connected to both the first and second variable volume means.
 23. In the heat converter assembly as set forth in claim
 22. wherein: a. a second bi-directional valve is connected between the first and second variable volume means, b. a second heat exchanger means is connected between the first and the second bi-directional valve, and c. the second bi-directional valve means includes means for alternately connecting the first and second variable valve means, and the second variable volume means with the second heat exchanger means.
 24. In the heat converter assembly as set forth in claim 23, wherein: a. heat regenerator means is interconnected between the first and second variable volume means. 